84 SURVEYS OF FOREST RESERVES. 



WESTERN SLOPE. 



West of the main range of the Rockies the Lewis and Glarlie Eeserve 

 includes practically the whole of the watersheds of Swan Eiver, which 

 empties into Flathead Lake, and of the South Fork of the Flathead 

 Eiver, together with the head waters of the Middle Fork of the same 

 stream. All of these streams flow in a northerly direction. Swan 

 Eiver and the Soutli Fork are separated by the Kootenai Eange, which 

 bounds the drainage area of the South Fork on the west. West of 

 Swan Eiver is the Mission Eange, while to the south of both these 

 streams are parts of the watersheds of the Big Blackfoot and other 

 streams tributary to Clarks Fork of the Columbia. Less rugged and 

 broken than the Eastern Slope, the Western is still sparsely settled 

 and very difficult of access. It contains some of the least known areas 

 in the United States. 



THE FOREST, WESTERN 8LOPK. 



The valleys of Swan Eiver and of the South and Middle forks of the 

 Flathead Eiver are comparatively uniform in sylvicultural character. 

 That of Swan Eiver may be said to occupy a somewhat intermediate 

 position between the broad agricultural lands of the Flathead Valley, 

 and the steeper and more densely wooded slopes of the valley of the 

 South Fork. It is, however, a true forest region, and almost wholly 

 unfit for agriculture. The lower portions of these valleys are occupied 

 by dense forests of coniferous trees whose principal components are 

 lodge pole pine and larch. Other trees are the western white pine, the 

 Douglas fir (red iir), and the western yellow pine. In the upper stretches 

 of Swan Eiver, as well as in the watershed of the Big Blackfoot, the 

 yellow pine forms over considerable areas practically the only forest 

 growth. The upper portion of the valley of the Middle Fork appears 

 to be covered principally with lodge-pole pine and Engelmann spruce. 



A description of the forests of the South Fork will serve to indicate 

 as well the character of the lower valleys of Swan Eiver and the Middle 

 Fork within the reserve. 



This forest is a dense, tall, and rich body, composed chiefly of valua- 

 ble kinds of trees, of which the larch is easily first in economic impor- 

 tance. The reproduction of the less valuable kinds is more vigorous 

 than that of the more desirable species, a condition unfortunately very 

 uncommon in forest regions. 



The western larch reproduces itself freely only in the open and on 

 land from which fires have not yet driven all the humus. Impatient of 

 shade, it does not, thrive under the cover of other trees. It is rapid in 

 growth, with thick bark, and even in comparatively early youth resists 

 fire well. Its average dimensions are roughly as follows : Height, 150 

 feet; diameter, 3 feet; length of clear trunk, 75 feet. 



The mountain white pine (silver pine)j next to the larch in economic 

 value, or perhaps sometimes surpassing it in the early stages of lumber 

 development, here reaches almost the same average size. It is, how- 

 ever, far behind the larch in number of individuals, aud, indeed, is by 

 no means common in the Swan Eiver drainage. 



The Douglas fir (red fir) occurs, on the whole, at slightly higher eleva- 

 tions than the larch, although it is very frequently found in mixture with 

 It. In the open country it reproduces itself well, but seedlings are not 

 common under heavy shade. Its average dimensions may be given 

 roughly as follows : Height, 125 feet; diameter, 2.5 feet ; length of clear 

 trunk, 50 feet. 



